Does it matter that they are now selling their 8th generation MacBook Pro? After all, It carries the same meaning as "4th generation iPhone" or "3rd Generation iPad". Yet they don't call it "Macbook Pro 8". And the buyers don't mind it. They walk in, ask for a MacBook Pro, and Apple will happily sell them the latest revision.
The arbitrary numbering of the 90's has nowadays been replaced with the bizarre naming of current phones. What's the difference between the HTC EndeavorU, Ville, Primo, Pyramid, Vigor, Radar, and Eternity?
Apple is now naming the iPad just like the MacBook & iMac. For proof see the naming their images on their site, it's just called "iPad2012" [5]. In technical references, Apple names the Macbooks based on their release date. Ie: 15-Inch Late 2011 Macbook Pro. [6]. Each model has a distinct number and Identifier, ie: MD313/A, and an Identifier: MacBookPro8,2.
But that's meaningless to the end user. They just want a MacBook Pro. Or a Macbook Air. Apple's new iPad naming policy just makes sense. They name the product line. Because that's what really matters.
*1 - http://www.wired.com/wired/archive/5.06/apple.html
*2 - http://en.wikipedia.org/wiki/PowerBook#Timeline_of_portable_Macintoshes
*4 - http://en.wikipedia.org/wiki/MacBook_Pro#Technical_specifications
*5 - http://store.storeimages.cdn-apple.com/2416/as-images.apple.com/is/image/AppleInc/ipad2012-step0-ipad-gallery-01-zoom
*6 - http://support.apple.com/kb/SP644